1. Field of the Invention
This invention is related to parallel plate radiators and, more particularly, is directed towards parallel plate radiators whose design is integrated with and conformal to the ogive of a projectile's radome structure.
2. Description of the Prior Art
Conventional antenna designs utilized in projectiles are large, bulky, waveguide, coaxial or strip line structures that are mounted inside of the projectile's radome. Aside from the space they occupy, these antennas have to be designed to radiate through an air space as well as through the wall of the radome, which tends to make such systems inefficient.
Antenna designs which are incorporated into and integral with a nose cone of a projectile are known, as exemplified by my prior U.S. Pat. No. 3,798,653. In my prior patent there is disclosed a small, compact, and efficient antenna that utilizes very little space and is employed on the tip of a projectile. The antenna therein described is in the form of a nose cone body having an electrically conductive inner surface which extends about the base of the nose cone and partially coats the outside thereof. The antenna is excited by a coaxial probe connected to the metal coating on the inside of the nose cone.
While compact, my earlier antenna is limited in versatility and hence, in usefulness. Being but a single radiating element, by earlier system is necessarily limited in its possible radiation patterns, modes of excitation, and the like. Further, the solid conductive inner coating utilized precludes the use of that antenna with additional antennas or antenna systems positioned interiorly of the nose cone, the solid copper ground plane being substantially opaque to higher frequencies.
Open circuit parallel plate radiators are also known, and generally consist of a ground plane on top of which is placed a variably sized metallic radiating element in an open-circuit relationship. While useful, such designs have inherent design limitations inasmuch as the radiation frequency or tuning is controllable only as a function of the size of the radiating element.
It is therefore apparent that it would be highly advantageous if an improved radiating element could be provided which is at least as compact as that presented in my prior patent discussed above, but which further adds multi-function versatility to the design of projectile antenna systems.